Stability of Platinum‐Group‐Metal‐Based Electrocatalysts in Proton Exchange Membrane Fuel Cells

Abstract Proton exchange membrane fuel cells (PEMFCs) have attracted significant interest as a promising alternative technology to the combustion engine to power next‐generation vehicles with zero emission. Among the various technological targets, system cost and durability are currently identified as the main obstacles toward large‐scale implementation of PEMFCs. Platinum‐group‐metal‐based (PGM‐based) catalysts are the most efficient catalyst for the rate‐limiting cathodic oxygen reduction reaction in PEMFCs and take the highest share in the cost breakdown. Therefore, the stability of PGM‐based electrocatalysts plays a significant role in the development of PEMFCs. This review will summarize the recent progress made on the understanding of both the fundamental chemical and structural stability of PGM‐based catalysts, and their durability in operational PEMFC devices. It calls for systematic studies on the chemical, structural, and operational durability of the PGM‐based catalyst and the need to coin practical descriptors for catalyst design with both superior activity and durability for cost‐effective and high‐performance PEMFCs.